Screening plant



July 1, 1930. H. BINTE Er AL 1,769,413

SCREENING PLANT Filed Sept. 6. 1928 A TTORN Patented July 1, 1 930 UNITED STATES-PATENT OFFICE HANS BINTE, OF BERLIN-SPANDAU, AND WERNER PIPKORN, OF BERLIN, GERMANY, ASSIGNORS-TO BAMAG-MEGUIN AKTIENGESELLSCHAFT, OF BERLIN, GERMANY, A

CORPORATION OF GERMANY SCREENING PLANT 5 Application filed September a, race, Serial No. 304,280, and in Germany May 7, 1928.

This invention relates to a screening plant with .mass-balanced screens suspended in a frame by means of guide rods, andworking in opposite directions. It differs from known arrangements of this kindin that the screens are not coupled together in a ositivemanner, but are merely connecte together indirectly by means of the frame, and in that their movement is regulated, by means of a triple kind of elastic damping devices, in

such a way that the entire system is set in motion vby a single connecting rod, and changes in the number of revolutions of the motive machine produce changes in the stroke of the screening movement without affecting the period of oscillation of the.

screens.-

The arrangement of the elastic damping said devices; to the suspension of the screens on the frame, by which means their period of oscillation is regulated; and to the connection of the point of application of the connecting rod which acts on one ofthe screens.

These three elastic dampings acting on the system at three different points of the three different reciprocating movements (thrustrod movement, screen movement and frame movement) co-act in such a manner than on starting, the movement of the connecting rod is smoothly and gradually transformed into the movement of the screen with which it is directly connected, and then the movement ofthis screen is transmitted,through the agenc of the now oscillating frame, to the secon positely directed oscillation, until a certain period of oscillation, specific for the entire system, is attained, the maintenance of which requires a minimum of motive power.

The elastic damping of the connecting rod, is so calculated that said damping ceases to operate when the normal working oscillation is attained; that is to say the spring interposed between the screen and the connecting rod then acts like a rigid member.

.In view of the action to beobtained, the values of the elastic damping of the screen screen, which is set in periodic op-' movement and the frame movement also hear a certain relation to the damping of the connecting rod and to each other. The elasticity of all three dampings is such thatthe energy stored up, every time, during the one direc ping progressive movement of the material on the screens.

I For the purpose of maintaining a certain maxlmum oscillation of the screens, means may be provided for automatically regulating the speed of the motive machine.

Atypical embodiment of the invention is illustrated on the accompanying drawing, in which Fig. 1 is a side elevation (that portion of the frame. situated in the plane of the drawing and to the right ofthe line of fracture X--X, being removed) and Fig. 2 is aplan.

In the embodiment illustrated, two independent screens 1) and b are mounted in series, at diiferent levels, in a frame a of box or similar type, being movably suspended by obliquely disposed parallel guide rods 0.

The frame a is supported, with the interposition of rollers e, on a sub-structure d, and the movement of the frame on said rollers is restricted and damped by springs f arranged between the frame and the sub-structure Said springs f are preferably located midway of the length of the frame, but they may also be disposed in any other suitable place.

The upper screen I) is driven by a motor 9 secured on the frame a and acting through an eccentric h and a connecting rod 71, which 1s connected w1th said screen 6 1n a nonrigid manner, being elastically attached l-.2;

thereto by means of a spring is so that, when the connecting rod is set in motion, said spring is first stretched, but co-acts in the system, like a rigid member, when the working speed is attained.

The oppositely-directed motion of the second screen I) is produced b means of spring devices Z: 1 the former 0 which transmits the movement of the connecting rod a, or

screen 6, to the frame a,.whilst the second ly swinging screen, a short time after the motor 9 is set in motion executes a movement opposite to the movement of the screen 6. This counter movement is brought about b the use as an intermediate slide between t e two screens of the frame whose mass far exceeds the mass of the two screens and in this manner the frame has a movement independent of all others.

Any change which may occur in the phase does not effect an efiicient working of the screen.

\Vhile the motor is running at---normal working speed and the connecting rod 2' is describing a corresponding number of strokes, the oscillations of all the moving masses in the plant are balanced in such a way that the apparatus is kept running by a minimum amount of force, which is inferior to the elasticity of the spring is, the latter therefore acting as a rigid member.

Since, apart from the stroke (which may be adjustable) of the eccentric, the amplitude of movement of the screens is dependent on the speed of the motor, provision is made, according to the invention, for automatically regulating the motor speed. For this purpose, there is inserted in the circuit of the working current a'series resistance which operates in the following manner :If, from any cause, the speed of the motor increases to an undue extent, and the stroke of the screens 6: b consequently becomes excessive, an. electrical resistance 0 is connected up in the working circuit by means of a stop we disposed on the screen I) and acting through lever mechanism n: 1-, so that the motor slows down at once. During the consequent reduction in the stroke of the screen, the resistance is slowly cut out again, automatically, by reason of the fact that the switch lever n is returned to its normal position by the action of a damping return device p.

In order to prevent clogging of the screen, for example in screening wet coal, provision is made for increasing the working current (independently of the aforesaid automatic regulating device) by switching out a special series resistance, and thereby intentionally increasing the stroke, at certain intervals, be 0nd that which is generall desirable.

aving now fully describe our invention what we claim and desire to secure by Letters Patent is 1. A screen plant comprising, in combination, mass-balanced screens, a frame, a stationary sub-structure adapted to support said frame, elastically damped connecting means coupling said frame to said sub-structure, means whereby said screens are suspended in said frame, elastically damped connecting means coupling each screen tosaid frame independently, reciprocating means, and elastically damped connecting means coupling said reciprocating means to one screen thereby causing the screens to oscillate in opposite directions.

2. A screening lant comprising, in combination, mass-ba anced screens, a frame, a stationary sub-structure adapted to support said frame, elastically damped connecting means coupling said frame to said sub-structure means whereby said screens are suspen ed in said frame, elastically damped connecting means coupling each screen to said frame independently, a connecting rod, rotary driving means on said frame adapted to reciprocate said rod, and elastically damped connecting means coupling said rod to one screen, thereby causing the screens to oscillate in opposite directions.

3. A screening plant comprising, in combination, mass-balanced screens, a frame, a stationary sub-structure adapted to support said frame, oppositely acting spring means connecting said frame to said sub-structure, means whereby said screens are suspended in said frame, elastically damped connecting means coupling eachscreen to said frame independently, reciprocating means, and oppos tely acting spring means connecting said reclprocating means to one screen thereby causing the screens to oscillate in opposite directions.

4. A screening plant comprising, in combination, mass-balanced screens, a frame, a stationary sub-structure adapted to support saidframe, elastically damped connecting means coupling said frame to said sub-structure, means whereby said screens are suspended in said frame, oppositely acting spring means connecting each screen to said frame independently, reciprocating means,

and elastically damped connecting means said rod, and oppositely acting spring means connecting sai rod to one screen thereby causing t e screens to oscillate in opposite directions.

6. A screening plant comprising, in combination, mass-balanced screens, a frame, a stationary sub-structure adapted to support said frame, elastically damped connecting means coupling said frame to said sub-structure, means whereby said screens are suspended in said frame, elastically damped connecting means coupling each screen to said frame independently, reciprocating means, means for regulating automatically the speed of operation of said reciprocating means, and elastically damped connecting means coupling said reciprocating means to one screen, thereby causing the screens to oscillate in opposite directions.-

7. A screening plant comprising, in combination, mass-balanced screens, a frame, a stationary sub-structure adapted to support said frame, elastically damped connecting means coupling said frame to said sub-structure,- means whereby said screens are suspended in said frame, elastically damped connecting means coupling each screen to said frame independently, a rigid connecting element, rotary driving means on said frame adapted to reciprocate said element, elastically damped connecting means coupling said element to one screen thereby causing the screens to oscillate in opposite directions, a stop member on one of the screens, a switch on'said frame operable by said member when said driving means exceeds normal speed, and a control device in operative connection with said switch so as automatically to regulate the speed of said driving means.

8. A screening plant comprising, in combination, mass-balanced screens, a frame, a stationary sub-structure adapted to support said frame, elastically damped connecting means coupling said frame to said sub-structure, means whereby said screens are suspended in said frame, elastically damped connecting means coupling each screen to said frame independently, a rigid connecting element, an electric motor on said frame adapted to reciprocate said element, elastically damped connecting means coupling said element to one screen thereby causing the screens to oscillate in opposite directions, a stop member on one of the screens, a switch on said frame operable by said member when said motor exceeds normal speed, and a variable resistance in series with said motor and operable by said switch so as automatically to regulate the speed of said driving means.

9. A screening plant comprising, in combination, mass-balanced screens, a frame, a stationary sub-structure adapted to support said frame, oppositely acting spring means connecting said frame to said sub-structure,

means whereby said screens are suspended in said frame, oppositely acting spring means connecting each screen to said frame independently, reciprocating means, means for and elastically damped connecting means coupling said reciprocating means to one screen, said reciprocating means having elasticity and being dimensioned to act as a rigid member at normal screening speed.

11. A screening plant comprising, in combination, mass-balanced screens, a frame, a stationary sub-structure adapted to support said frame, elastically damped'connecting means coupling said frame to said sub-structure, springy guide rods whereby said screens are suspended from said frame, elastically damped connecting means coupling each screen to said frame independently, reciprocating means, and elastically damped connecting means coupling said reciprocating means to one screen, thereby causing the screens to oscillate in opposite directions.

12. A screening plant comprising, in combination, mass-balanced screens, a frame, a stationary sub-structure adapted to support said frame, oppositely acting spring means connecting said frame to said sub-structure, springy guide rods whereby said screens are suspended from said frame, oppositely acting spring means connecting each screen to said frame independently, a connecting rod, rotary driving means on said frame adapted to reclprocate said rod, and oppositely acting spring means connecting said rod to one screen, said reciprocating means having elasticity and being dimensioned to act as a rigid member at normal screening speed.

13. A screening plant comprising, in combination, mass-balanced screens, a frame, a stationary sub-structure adapted to support said frame, oppositely acting spring means connecting said frame to said sub-structure, springy guide rods whereby said screens are suspended from said frame, oppositely acting spring means connecting each screen to said frame independently, a connecting rod, rotary driving means on said frame adapted to reciprocate said rod, oppositely acting spring means connecting said rod to one screen and so made in relation to the spring means between the frame and screens and between the frame and sub-structure that 'at normal speed the said connecting means between said screen and rod acts as a rigid member, a stop member on one of said 5 screens, a switch on said frame operable by said member when said driving means exceeds normal speed, and a control device in operative connection with said switch so asautomatically to regulate the speed of said drivin means.

14. screening plant comprising, in combination, a pair of mass-balanced screens, a frame, a fixed sub-structure adapted to support said frame, elasticall damped connecting means coupling said rame to said substructure, springy guide rods whereby said" screens are suspended in said frame, inclined members secured to said frame and slidably engaged by one of said screens, se arate inclined members secured to said rame and slidably engaged by the other screen, springs interposed between said frame and screens on each inclined member, reciprocating means, and elastically damped connecting means 5 coupling said reciprocating means to one screen so as to ensure oscillation of the screen in opposite directions.

15. A screening plant comprising in combination a pair of mass-balanced screens, a

frame of open box-shape, a fixed sub-structure adapted to support said frame, oppositely acting spring means connecting said frame to said sub-structure, parallel inclined guide rods whereby said screens are suspended from said frame, inclined members secured to said frame and slidably engaged b one of said screens, separate inclined mem ers secured to said frame and slidably engaged by the other screen, springs interposed between said frame and screens on each inclined member, 'a rigid connecting element, an electric motor on said frame, drivin connection between said motor and said e ement,.and oppositely acting spring means connecting said element to one screen so as to effect oscillation of the screens in opposite directions.

In testimony whereof we aflix our signatures.

HANS BINTE.

WERNER PIPKORN. 

